Mercury boiler



y 1932- a. P. COULSON, JR 1,861,264

METRCURY BOILER File d June 14. 1929 2 Sheets-Sheet 1 Fig.

Inventor Bevis I? CouJsomJ-n, v bg His Atcor'heg.

Patented May 31, 1932 UNITED STATES PATENT FFIE BEVIS P. COULSON, JR.,OF SOHENECT'ADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, ACORPORATION" OF NEW YORK MERCURY BOILER Application filed .Tune 14,

The present invention relates to mercury boilers, and especially tomercury boilers of the type disclosed in the a plication of L. R. Emmetand mysel Serial No. 306,486 filed September 17 1928.

The object of my invention is to provide a mercury boiler having animproved construction and arrangement of boiler tubes, and for aconsideration of what I believe to be novel and my invention, attentionis directed to the following specification and the claims appendedthereto.

In the drawings, Fig. 1 is a sectional view of a boiler structureembodying my inven tion mounted in a furnace; Fig. 2 is a detailsectional view on a larger scale of the upper end of one of the boilertubes; Fig. 3 is a detail plan view of the inside of one of the boilerdrums; Fig. 4 is a transverse sectional view through one of the boilerdrums, and Fig. 5 is a detail perspective view of a part of a boilertube.

Referring to the drawings, 1 indicates a furnace in which the boiler ismounted. Any suitable fuel may be burned in it. In the present instanceit is shown as being an oil fired boiler, 2 indicating an oil burner and3 indicating the combustion chamber. The products of combustion passvertically upward to the top of the furnace and are discharged therefromlaterally through conduit 4.

The boiler may comprise a number of units 5 each complete in itself.These units are mounted side by side in the furnace and are arranged todeliver elastic fluid in parallel through pipes 6 to a common header ordrum 7 located at the forward end of the furnace. From header or drum 7the elastic fluid is conveyed through pipes 8 to a second header or drum9 located at the rear of the furnace. Connected to header or drum 9 is aconduit 10 through which the elastic fluid is conveyed to a point ofconsumption which may be, for example, an elastic fluid turbine. Onlyone of the boiler units is shown in the drawing, but it will beunderstood that the several boiler units may be alike and are mountedside by side in spaced relation to each other. They are supported in thefur- 1929. Serial No. 370,995.

nace in any suitable manner.

instance they are shown as being suspended from I-beams 11 by means oftie rods 12.

Each boiler unit comprises a casing or drum 13 which is closed at itsends by suitable heads. Depending from the under side of drum 13 are a.number of boiler tubes 14., such tubes being flared slightly relativelyto each other and being arranged directly over the firebox whereby theproducts of combustion pass vertically over them. Liquid mercury issupplied to the boiler drum by a conduit 13a which may lead from anysuitable source of supply. 136 indicates the liquid level gage for theboiler.

The boiler construction so far described is of the type disclosed in theabove-mentioned application. My invention relates more particularly toan improved form of boiler tube 14 and to an improved arrangement of thetubes in the boiler drum.

Each boiler tube comprises an outer tube 15 in which is located atubular core 16. Outer tube is closed at its lower end, being providedwith a rounded bottom, and at its top it is fastened in an opening indrum 13, preferably by welding, as is indicated at 17, Fig. 2. Core 16comprises a thick wall tube of the same general contour as the outertube. It is held in spaced relation to the outer tube by suitable meanssuch as a number of short longitudinally extending ribs 18 which may beformed by pressing outwardly some of the metal of the core. The lowerend of the core terminates short of the bottom of the outer tube and isheld in spaced relation to the bottom of the outer tube by one or morespacers or projections 19. lVith this arrangement it will be seen thatthe passage through the core, which passage is designated 20,communicates at its lower end with an annular passage 21 formed betweenthe core and the inner surface of outer tube 15.

Core 16 may be formed with advantage of two spaced tubes welded togetherat their upper and lower ends, as is indicated at 22, the space betweenthe tubes at the upper end being closed by a disc 22 The dead spaceformed in the core between the tubes is preferably filled with air,although it may be filled In the present with some other substance. Thepurpose of this is to provide an effective heat insulation between thepassage 20 through the inner tube or core and the outer tube to preventthe transfer of heat to the liquid while flowing down through passage20. This is important in a mercury boiler, it being essential that alarge quantity of relatively cool mercury be delivered continuously tothe end of the tube which is exposed to heat radiation because mercurywhen not boiling is a much better heat remover than it is when boiling.Pref erably the inner tube of the core has one or more bends in it, asshown particularly in Fig. 1, so as to provide a small amount offlexibility in such tube to take care of unequal expansion of the parts.

Core 16 terminates short of the upper end of outer tube 15, and locatedabove it is a block 23, the lower end of which rests on the upper end ofcore 16. The outer surface of block 23 is spaced from the inner surfaceof tube 15 to provide an annular space which forms a continuation ofpassage 21, the block being held by pins or projections 24:. Block 23 isprovided with a central passage 25 which flares outwardly at its upperend to provide a sort of funnel shaped opening 26. At its lower end,passage 25 communicates with down tube passage 20. Preferably, the pipeforming passage 20 is extended upwardly into the lower end of passage 25so as to form a good connection between them. In block 23 are a seriesof circumferentially spaced slots 27 which extend longitudinally of theblock from its upper end to a point short of its lower end, and in eachslot are a number of partition walls 28 which slope downwardly. There isthus provided a series of downwardly sloping passages 29 which extendfrom the outside of block 23 to the central passages 25. Block 23 isheld down preferably by means of several angle bars 30 welded to theinner surface of the upper end of outer tube 15. Preferably formanufacturing reasons the upper end of the tube 15 is formed as aseparate piece, the point between the tube sections being indicated at31. Fastened to the upper end of tube 15 is a cone shaped discharge cap32 having a discharge opening 33 at its outer end. In outer tube 15 justinside the boiler drum is a passage 34. through which liquid mercury isfed from the drum to passage 25.

In order to decrease the space inside the boiler drum, there areprovided filler blocks 35 which are arranged in rows runninglongitudinally of the boiler drum and are spaced apart to providepassages 36 for the flow of mercury to the tubes. The blocks areprovided with recesses 37 in which the upper ends of the boiler tubesare located, the ar rangement being such that the liquid feed opening 34of each tube opens into a passage 36. This arrangement of the blockswhereby there are provided channels for the flow of liquid to the tubes,the feed openings for the tubes communicating with the channels, is ofsubstantial advantage in that it insures that there is always present asupply of mercury for each tube. The filler blocks are shown as beingfastened to the bottom of the drum by means of bolts 38, means beingprovided for spacing the blocks slightly from the walls of the drum asshown in Fig. 4. Preferably each block row is made in several pieces, asshown in Fig. 3, for convenience in handling. 39 indicates a separatormeans which extends longitudinally of the boiler drum above the ends ofthe tubes and is provided with one or more openings l0 for the escape ofvapor.

TVhen the boiler is in operation, mercury is fed to each tube throughits feed passage 34 and flows down through central passage 25 in block23 and passage 20 in the core to the lower end of the tube, and thenceup through the annular passage 21. As it flows upward through annularpassage 21 it is vaporized and the vapor and such mercury particles asare entrained with it are discharged from the upper end of vapor space21 and directed by cone shaped cap 32 to the discharge opening 33.Mercury particles striking the cone shaped cap 32 drop downward againinto the funnel shaped portion 26 of passage 25, from whence they flowdown through core passage 20. Thus it will be seen that mercury is fedcontinuously to each core passage by way of its feed passage 34 and alsofrom the funnel shaped end 26 of its block 23. Also, liquid mercury canflow through any of the passages 29 to the central passage 25, and moreor less of the liquid particles being carried upward by the vapor areseparated and returned through these passages 29 to passage 25 beforethe liquid particles reach the upper end of tube 15. The vapordischarged from the upper ends of the tubes strikes against theunderside of plate 39 and flows along it to the discharge opening oropenings 40. This serves to separate out any liquid particles in thevapor which may have escaped with it from the tubes.

It will be noted that a number of the passages 29 are located below thebottom of the boiler drum 13. This arrangement has the advantage thateven should the level of mercury in the boiler drop below that of thepas- 34, still there would be maintained a circulation of mercury in thetubes due to the mercury flowing from annular passage 21 back throughthe lower passages 29 to the central passage 25.

By extending the tubes 15 to a point well above the bottom of the boilerdrum, and feeding the liquid mercury to the tubes at a point below theirupper ends, the advantage is obtained that the vapor discharged from thetubes cannot interfere with the flow of liquid mercury to the centralcore passages. This arrangement, therefore, serves to make more sure acontinuous uninterrupted flow of liquid mercury to the tubes.

The liquid level of the mercury in the boiler drum during normaloperation would be in the vicinity of the tops of the filler blocks 35so that the mercury supplied to the tubes through the feed passages 34enters such passages from a point well below the surface of the mercuryin the boiler drum. This arrangement has the advantage that the mercuryis drawn always from below the liquid level in the boiler drum so thereis no danger of dirt accumulated on the surface of the mercury beingdrawn down into the tube.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. In a mercury boiler, the combination of a casing, an outer tube whichprojects through said casing to a point above the inner sur face of thecasing wall, a core in said outer tube in spaced relation thereto toprovide an up passage, said core having a passage for the down flow ofmercury, means providing vertically extending slots which connect the uppassage to the down passage from a point above the casing wall to apoint below the inner surface of the casing wall, and means forsupplying mercury from the casing to said down passage.

2. In a mercury boiler, the combination of a casing, an outer tube whichprojects through said casing to a point above the inner surface of thecasing wall, a core in said outer tube in spaced relation thereto toprovide an up passage, said core having a passage for the down flow ofmercury, means providing vertically extending downwardly sloping slotswhich connect the up passage to the down passage from a point above thecasing Wall to a point below the inner surface of the casing wall, and aconduit for con veying mercury from the casing to said down passage.

3. In a mercury boiler, the combination of a casing, a plurality ofboiler tubes depending therefrom, each boiler tube comprising wallswhich define an outer up passage and a central down passage, the upperends of said tubes projecting above the inner surface of the bottom wallof the casing, filler blocks in said casing spaced from each other toform channels, said blocks having recesses in their sides in which theupper ends of said tubes are located, and means providing passages whichconnect said channels to the down passages in said tubes.

4. In a mercury boiler, the combination of a casing, a plurality ofboiler tubes depending therefrom, each boiler tube comprising wallswhich define an outer up passage and a central down passage, the upperends of said tubes projecting above the inner surface of the bottom wallof the casing to a point above the normal liquid level in the boiler,cone shaped vapor discharge caps on the ends of said tubes, fillerblocks in the casing which define channels for the flow of mercury, andpassages connecting said channels to the down passages of the tubes.

5. A mercury boiler tube comprising an outer tube, a core in said outertube in spaced relation thereto to provide an up passage, said corehaving a down passage for the flow of mercury, means providingvertically extending downwardly sloping passages in the upper end of thecore directly adjacent to the admission end of the down passage whichconnect the up passage to the down passage, and a conduit which connectsone of said sloping passages to the outside of the outer tube andthrough which mercury may be supplied to the down passage, said conduitbeing located below the upper end of the outer tube.

In witness whereof, I have hereunto set my hand this 13th day of June,1929.

BEVIS P. COULSON, JR.

